Final answer:
The structure of a Cys2His2 zinc finger involves a coordination complex between a zinc ion and two cysteine residues and two histidine residues, forming a looped structure with a zinc finger motif.
Step-by-step explanation:
A Cys2His2 zinc finger is a structural motif commonly found in DNA-binding proteins. It consists of a zinc ion coordinated by two cysteine (Cys) residues and two histidine (His) residues in a tetrahedral arrangement. The zinc finger motif is typically part of a larger protein sequence and is involved in recognizing and binding to specific DNA sequences. The cysteine and histidine residues, which serve as ligands for the zinc ion, create a looped structure that allows the zinc finger to interact with the major groove of DNA.
This interaction is crucial for the protein's ability to bind selectively to specific DNA sequences and regulate various cellular processes, such as gene expression. The Cys2His2 zinc finger motif is characterized by its conserved arrangement of cysteine and histidine residues, contributing to its stability and functionality in DNA binding.
Understanding the structure of Cys2His2 zinc fingers provides insights into the molecular mechanisms underlying DNA-protein interactions and facilitates the study of transcription factors and other regulatory proteins involved in cellular processes.